Rhythm circuit: Best pots/wiring for smooth taper and no tone loss?

[alexpigment]

I recently did some work on my rhythm circuit in my Squier Deluxe JM to make it more useful. Since I use 250k pots in the lead circuit, I have dual 1meg pots in the rhythm circuit. That's effectively my "bright" channel, which works on all pickup positions. Unfortunately I find that the taper is terrible, so there's very little volume drop from 10 to 2, and then it drops way off after that. The tone pot is pretty much the same, although this is much less important to me, given that it's my bright channel. The pots are both Alpha A1M pots (audio taper).

I wanted to get an idea of the best combination of pots, wiring, etc so that the rhythm circuit stays considerably brighter, and remains bright as the volume pot goes down, all while keeping a linear-sounding taper. If I can keep the same bracket and roller wheels (these are Chinese JMJM components), that's a plus. I do have some B1M pots sitting around that I could try, but I don't want to rewire without some feedback. Anyone have any experience with achieving a similar goal?

[timtam]

The regular rhythm circuit has linear pots.

[alexpigment]

And in your experience this yields a smooth gradation from 10 to 0? Or is the design because they didn't have audio taper mini pots in the 50s/60s?

[timtam]

I'm not really the best person to ask about the rhythm circuit - never really liked/used it. But AFAIK the volume rolloff with linear pots is relatively smooth (the jag also has them in its rhythm circuit). But you're obviously in somewhat new territory with your dual 1meg pots there. BTW the stock rhythm circuit wiring perhaps prompted an earlier published diagram from Seymour Duncan that wired it differently (see below) - which I have in my notes as preventing volume loss with dialling down the tone control.

A linear volume pot also obviously works well in the lead circuit. So alternatively you could wire your rhythm circuit the same way as the lead circuit, just with your different pot values (and use one audio and one linear pot).

Early SD JM diagram that had modified rhythm circuit ...



Easiest to see the SD difference on its schematic, compared to the stock JM circuit I posted up-thread ....

[alexpigment]

When you say "preventing volume loss with dialling down the tone control", I read it as "causing tone loss by dialing down the volume control". That's the classic "50s wiring vs modern wiring" debate, and I find myself firmly in the 50s wiring camp - the small drop in volume from turning the tone knob down is way less noticeable to me - especially when your clean tone has a little bit of gain in it - than the tone loss when rolling the volume knob down. I'm definitely trying to keep it bright as possible, and I've got a treble bleed currently in there to help out.

At any rate, it sounds like there's no "magic bullet" here, so I'll try messing around with different configurations and see what happens. Thanks for the suggestions as always.

[timtam]

Neither are 50s wiring though (tone pot coming off middle lug of volume pot).
https://www.premierguitar.com/diy/mod-g ... pot-wiring

And I don't interpret what I had noted that way, as treble loss when dialling down the volume. I definitely wrote the note as I got it from the source who drew my attention to that rhythm circuit difference in the early SD diagram - as preventing volume loss when using the tone control. On the stock rhythm circuit the volume pot/output only sees what's come off the tone control. That's different from both modern wiring and 50s wiring (those being mostly a 'thing' in Les Paul circles). Having said all that I haven't tried the SD mod to see if there is indeed no volume loss with dialling down the tone control.

But we're speculating on what the sonic effect of all these mods will be. As you say, you may just have to try your original idea or other ideas to get your brighter rhythm circuit working the way you want.

[alexpigment]

I'm pretty sure you *always* have to choose one or the other downside when wiring a volume and tone. You either get a volume loss when turning down the tone, or a tone loss when turning down the volume. If there were a way to avoid both without introducing other things into the equation, I think we'd know about it by now I suspect that functionally the SD wiring is equivalent to 50s wiring, and that shared middle lug on the tone pot is probably the key (i.e. the output lug is shared with the wire that links the pots), but my brain is sharp enough to fully map this out in my head to prove it on paper alone.

Either way, I'll have to wait until after Christmas to really dig back into this one, and I'll report back any interesting findings.